Melatonin is a potential novel analgesic agent for osteoarthritis: Evidence from cohort studies in humans and preclinical research in rats.

Melatonin exhibits potential for pain relief and long-term safety profile. We examined the analgesic effects of oral melatonin on osteoarthritis (OA) and investigated the underlying mechanism. Using data from a UK primary care database, we conducted a cohort study in individuals with OA to compare the number of oral analgesic prescriptions and the risk of knee/hip replacement between melatonin initiators and hypnotic benzodiazepines (i.e., active comparator) initiators using quantile regression models and Cox-proportional hazard models, respectively. To elucidate causation, we examined the effects of melatonin on pain behaviors and explored several metabolites that may serve as potential regulatory agents of melatonin in the monoiodoacetate rat model of OA. Using data from another community-based cohort study, that is, the Xiangya OA Study, we verified the association between the key serum metabolite and incident symptomatic knee OA. Compared with the hypnotic benzodiazepines cohort (n = 8135), the melatonin cohort (n = 813) had significantly fewer subsequent prescriptions of oral analgesics (50th percentile: 5 vs. 7, 75th percentile: 19 vs. 29, and 99th percentile: 140 vs. 162) and experienced a lower risk of knee/hip replacement (hazard ratio = 0.47, 95% Cl: 0.30-0.73) during the follow-up period. In rats, oral melatonin alleviated pain behaviors and increased serum levels of glycine. There was an inverse association between baseline serum glycine levels and the risk of incident symptomatic knee OA in humans (n = 760). In conclusion, our findings indicate that oral melatonin shows significant potential to be a novel treatment for OA pain. The potential role of glycine in its analgesic mechanism warrants further investigation.

Phenotypes of osteoarthritis-related knee pain and their transition over time: data from the osteoarthritis initiative.

BACKGROUND: Identification of knee osteoarthritis (OA) pain phenotypes, their transition patterns, and risk factors for worse phenotypes, may guide prognosis and targeted treatment; however, few studies have described them. We aimed to investigate different pain phenotypes, their transition patterns, and potential risk factors for worse pain phenotypes. METHODS: Utilizing data from the Osteoarthritis Initiative (OAI), pain severity was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. We identified the activity-related pain phenotypes and estimated the transition probabilities of pain phenotypes from baseline to the 24-month using latent transition analysis. We examined the risk factors at baseline with the 24-month pain phenotypes and the transition of pain phenotypes. RESULTS: In 4796 participants, we identified four distinct knee pain phenotypes at both baseline and 24-month follow-up: no pain, mild pain during activity (Mild P-A), mild pain during both rest and activity (Mild P-R-A), and moderate pain during both rest and activity (Mod P-R-A). 82.9% knees with no pain at baseline stayed the same at 24-month follow-up, 17.1% progressed to worse pain phenotypes. Among "Mild P-A" at baseline, 32.0% converted to no-pain, 12.8% progressed to "Mild P-R-A", and 53.2% remained. Approximately 46.1% of "Mild P-R-A" and 54.5% of "Mod P-R-A" at baseline experienced remission by 24-month. Female, non-whites, participants with higher depression score, higher body mass index (BMI), higher Kellgren and Lawrence (KL) grade, and knee injury history were more likely to be in the worse pain phenotypes, while participants aged 65 years or older and with higher education were less likely to be in worse pain phenotypes at 24-month follow-up visit. Risk factors for greater transition probability to worse pain phenotypes at 24-month included being female, non-whites, participants with higher depression score, higher BMI, and higher KL grade. CONCLUSIONS: We identified four distinct knee pain phenotypes. While the pain phenotypes remained stable in the majority of knees over 24 months period, substantial proportion of knees switched to different pain phenotypes. Several socio-demographics as well as radiographic lesions at baseline are associated with worse pain phenotypes at 24-month follow-up visit and transition of pain phenotypes.

In-hospital complications and readmission patterns in 13,937 patients with developmental dysplasia of the hip undergoing total hip arthroplasty: Evidence from the Chinese national database.

PURPOSE: Clarifying the prognosis and readmission patterns of patients with developmental dysplasia of the hip (DDH) following total hip arthroplasty (THA) would provide important references for clinical management for this population. Using the Chinese national inpatient database (i.e., Hospital Quality Monitoring System [HQMS]), we aimed to compare in-hospital complications and readmission patterns following THA in patients with DDH and primary osteoarthritis (OA). METHODS: Patients undergoing THA for DDH and OA between 2013 and 2019 were identified using the HQMS. Demographics and clinical characteristics were compared between the two groups. After propensity score matching, in-hospital complications and readmission patterns were compared using a logistic regression model. RESULTS: According to the analysis of 13,937 propensity-score matched pairs, there were no significant differences in the incidence of in-hospital death (0.01 % vs 0.04 %, P = 0.142), transfusion (8.09 % vs 7.89 %, P = 0.536), wound infection (0.31 % vs 0.25 %, P = 0.364), deep venous thrombosis (0.45 % vs 0.43 %, P = 0.786), pulmonary embolism (0.03 % vs 0.05 %, P = 0.372) or all-cause readmission (2.87 % vs 3.12 %, P = 0.219) between two groups. However, DDH patients had higher surgical readmission rates than OA patients (1.43 % vs 1.14 %, P = 0.033). When analyzing causes of surgical readmission, DDH patients had increased risk of dislocation (0.37 % vs 0.21 %, P = 0.011) and aseptic loosening (0.17 % vs 0.07 %, P = 0.024) than OA patients. CONCLUSION: DDH patients had an increased risk of surgical readmission following THA, mainly driven by dislocation and aseptic loosening, which should be recognized and appropriately prevented.

Trends, complications, and readmission of allogeneic red blood cell transfusion in primary total hip arthroplasty in china: a national retrospective cohort study.

INTRODUCTION: Decrease in allogenic red blood cell (RBC) transfusion rates following total hip arthroplasty (THA) has been reported in the United States, but whether other countries share the same trend remains unclear. Additionally, the relation of allogenic RBC transfusion to the risk of complications in THA remains controversial. Using the Chinese national inpatient database, the current study aimed to examine trends, complications, charges, and readmission patterns of allogeneic RBC transfusion in THA. MATERIALS AND METHODS: Patients undergoing primary THA between 2013 and 2019 were included, and then stratified into the transfusion and the non-transfusion group based on the database transfusion records. A generalized estimating equation model was used to investigate trends in transfusion rates. After propensity-score matching, a logistic regression model was used to compare the complications, rates and causes of 30-day readmission between two groups. RESULTS: A total of 10,270 patients with transfusion and 123,476 patients without transfusion were included. Transfusion rates decreased from 19.11% in 2013 to 9.94% in 2019 (P for trend < 0.001). After matching, no significant differences in the risk of of in-hospital death (odds ratio [OR], 4.00; 95% confidence interval [CI] 0.85-18.83), wound infection (OR 0.72; 95%CI 0.45-1.17), myocardial infarction (OR 1.17; 95%CI 0.62-2.19), deep vein thrombosis (OR 1.25; 95%CI 0.88-1.78), pulmonary embolism (OR 2.25; 95%CI 0.98-5.17), readmission rates (OR 1.07; 95%CI 0.88-1.30) and readmission causes were observed between two groups. However, the transfusion group had higher hospitalization charges than the non-transfusion group (72,239.89 vs 65,649.57 Chinese yuan [CNY], P < 0.001). CONCLUSIONS: This study found that allogeneic RBC transfusion in THA was not associated with the increased risk of complications and any-cause readmission. However, the currently restrictive transfusion policy should be continued because excessive blood transfusion may increase the socioeconomic burden.

Deep learning-based automatic pipeline for quantitative assessment of thigh muscle morphology and fatty infiltration.

PURPOSE: Fast and accurate thigh muscle segmentation from MRI is important for quantitative assessment of thigh muscle morphology and composition. A novel deep learning (DL) based thigh muscle and surrounding tissues segmentation model was developed for fully automatic and reproducible cross-sectional area (CSA) and fat fraction (FF) quantification and tested in patients at 10 years after anterior cruciate ligament reconstructions. METHODS: A DL model combining UNet and DenseNet was trained and tested using manually segmented thighs from 16 patients (32 legs). Segmentation accuracy was evaluated using Dice similarity coefficients (DSC) and average symmetric surface distance (ASSD). A UNet model was trained for comparison. These segmentations were used to obtain CSA and FF quantification. Reproducibility of CSA and FF quantification was tested with scan and rescan of six healthy subjects. RESULTS: The proposed UNet and DenseNet had high agreement with manual segmentation (DSC >0.97, ASSD < 0.24) and improved performance compared with UNet. For hamstrings of the operated knee, the automated pipeline had largest absolute difference of 6.01% for CSA and 0.47% for FF as compared to manual segmentation. In reproducibility analysis, the average difference (absolute) in CSA quantification between scan and rescan was better for the automatic method as compared with manual segmentation (2.27% vs. 3.34%), whereas the average difference (absolute) in FF quantification were similar. CONCLUSIONS: The proposed method exhibits excellent accuracy and reproducibility in CSA and FF quantification compared with manual segmentation and can be used in large-scale patient studies.

Anteromedial Portal Technique, but Not Outside-in Technique, Is Superior to Standard Transtibial Technique in Knee Stability and Functional Recovery After Anterior Cruciate Ligament Reconstruction: A Network Meta-analysis.

PURPOSE: To compare the postoperative outcomes of 4 different femoral drilling techniques in anterior cruciate ligament reconstruction. METHODS: Three databases were searched for randomized controlled trials comparing any 2 or more of the following femoral drilling techniques in anterior cruciate ligament reconstruction: standard transtibial (sTT), anteromedial portal (AMP), outside-in (OI), or modified transtibial (mTT) technique. A Bayesian network meta-analysis was performed to assess postoperative stability and functional recovery in terms of the side-to-side difference (measured by arthrometry), Lachman test, pivot-shift test, International Knee Documentation Committee subjective and objective scores, Lysholm score, and Tegner score. The Fisher exact probability test and χ2 test were used to compare the incidences of infection and graft rupture, respectively. RESULTS: We included 20 randomized controlled trials involving 1,515 patients. The AMP technique showed a lower side-to-side difference (standardized mean difference, -0.33; 95% credible interval [CrI], -0.53 to -0.12), higher negative rate on the pivot-shift test (odds ratio, 2.19; 95% CrI, 1.38 to 3.44), and higher International Knee Documentation Committee objective score (odds ratio, 3.13; 95% CrI, 1.42 to 7.82) than the sTT technique. However, knee stability and functional outcomes did not differ significantly between the OI and sTT techniques. Safety outcomes of the mTT technique were unavailable. The incidence of graft rupture was 5.20% for the OI technique, 2.27% for the AMP technique, and 1.51% for the sTT technique. The OI technique had a significantly higher incidence of graft rupture than the sTT technique (χ2 = 4.421, P = .035). No significant difference in the incidence of infection was found between the sTT, AMP, and OI techniques (P = .281). CONCLUSIONS: The AMP technique, but not the OI technique, was superior to the sTT technique in knee stability and functional recovery. The OI technique had a higher incidence of graft rupture than the sTT technique. There was no significant difference between the AMP and OI techniques or between the mTT technique and any other femoral drilling technique. LEVEL OF EVIDENCE: Level II, meta-analysis of Level I and II studies.

Burden and Characteristics of Revision Total Knee Arthroplasty in China: A National Study Based on Hospitalized Cases.

BACKGROUND: National epidemiological data in China are absent for revision total knee arthroplasty (TKA). This study aimed to investigate the burden and characteristics of revision TKA in China. METHODS: We reviewed 4,503 revision TKA cases registered in the Hospital Quality Monitoring System in China between 2013 and 2018 using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Revision burden was determined by the ratio of the number of revision procedures to the total number of TKA procedures. Demographic characteristics, hospital characteristics, and hospitalization charges were identified. RESULTS: The revision TKA cases accounted for 2.4% of all TKA cases. The revision burden showed an increasing trend from 2013 to 2018 (2.3% to 2.5%) (P for trend = .034). Gradual increases in revision TKA were observed in patients aged > 60 years. The most common causes for revision TKA were infection (33.0%) and mechanical failure (19.5%). More than 70% of the patients were hospitalized in provincial hospitals. A total of 17.6% patients were hospitalized in a hospital outside the province of their residence. The hospitalization charges continued to increase between 2013 and 2015 and remained roughly stable over the next three years. CONCLUSIONS: This study provided epidemiological data for revision TKA in China based on a national database. There was a growing trend of revision burden during the study period. The focalized nature of operations in a few higher volume regions was observed and many patients had to travel to obtain their revision procedure.

Associations between adipokines gene polymorphisms and knee osteoarthritis: a meta-analysis.

BACKGROUND: Adipokines gene polymorphisms are speculated to be associated with the risk of knee osteoarthritis (OA), but evidence remains conflicting. This study therefore aimed to examine whether associations exist between adipokines gene polymorphisms and knee OA by considering the evidence collected from eligible studies through a meta-analysis. METHODS: A systematic search was performed on PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang up to March 31, 2020. Meta-analysis was carried out by focusing on the associations between adipokines gene polymorphisms and knee OA with the allele model, dominant model, and recessive model. RESULTS: The present meta-analysis included 5 eligible studies for ADIPOQ rs1501299 with 1,021 cases and 1,097 controls, 3 eligible studies for ADIPOQ rs2241766 with 549 cases and 544 controls, 3 eligible studies for LEPR rs1137101 with 808 cases and 856 controls, 2 eligible studies for VISFATIN rs4730153 with 339 cases and 680 controls and 2 eligible studies for VISFATIN rs16872158 with 339 cases and 680 controls. Significant association was observed between LEPR rs1137101 and knee OA in the overall population (recessive: OR = 0.40, 95% CI 0.21-0.79). Limited data revealed that associations may exist between ADIPOQ rs2241766 and knee OA in Asians (dominant: OR = 1.35, 95% CI 1.03-1.78), between VISFATIN rs4730153 and knee OA in Asians (allele: OR = 0.58, 95% CI 0.41-0.83; dominant: OR = 0.57, 95% CI 0.39-0.83), and between VISFATIN rs16872158 and knee OA in Asians (allele: OR = 1.84, 95% CI 1.26-2.68; dominant: OR = 1.94, 95% CI 1.31-2.89). CONCLUSIONS: Adipokines gene polymorphisms may be associated with knee OA. The association was observed in LEPR rs1137101 in the present study. In addition, limited data revealed that associations may also exist in ADIPOQ rs2241766, VISFATIN rs4730153 and VISFATIN rs16872158. PROSPERO REGISTRATION: CRD42020187664.

Intra-Articular Magnesium Plus Bupivacaine Is the Most Effective and Safe Postoperative Analgesic Option Following Knee Arthroscopy: A Network Meta-analysis.

PURPOSE: To evaluate the comparative efficacy and safety of single-dose intra-articular injection of commonly used analgesics after knee arthroscopy. METHODS: A systematic literature review was done to search for randomized controlled trials (RCTs) published from database inception to October 1, 2020, that compared analgesics (i.e., morphine, bupivacaine, ropivacaine, and magnesium alone or in combination) with placebo or each other after knee arthroscopy. The primary outcomes were postoperative pain intensity at 2 hours and 24 hours. Secondary outcomes included the time to first analgesic request, number of patients requiring supplementary analgesics and side effects. We estimated summary standardized mean differences (SMDs) or odds ratios with 95% credible intervals (95% CrIs) using Bayesian network meta-analysis with random effects. RESULTS: In total, 78 randomized controlled trials comprising 4,425 participants were included. Compared with placebo, magnesium plus bupivacaine was most likely to be effective in relieving pain at both 2-hour (SMD = -3.81, 95% CrI -5.28 to -2.35) and 24-hour after surgery (SMD = -2.81, 95% CrI: -4.29 to -1.30). Following was morphine plus bupivacaine (2-hour: SMD = -2.19, 95% CrI -3.05 to -1.31; 24-hour: SMD = -1.44, 95% CrI -2.14 to -0.73) and bupivacaine alone (2-hour: SMD = -1.66, 95% CrI -2.33 to -0.98; 24-hour: SMD = -0.67, 95% CrI -1.22 to -0.07); ropivacaine alone and magnesium alone were not effective on pain relief. The interval time to first analgesic request was significantly extended compared with placebo except for ropivacaine alone and magnesium alone. The number of patients requiring supplementary analgesics was reduced in all groups except ropivacaine alone. No statistically significant difference was found between any studied analgesics or placebo with regard to side effects. CONCLUSIONS: Of 6 common postoperative intra-articular analgesics, magnesium plus bupivacaine provides the most effective pain relief without increasing short-term side effects after knee arthroscopy. LEVEL OF EVIDENCE: Level II, meta-analysis of Level I and II studies.

Association Between Dietary Selenium Intake and the Prevalence of Nonalcoholic Fatty Liver Disease: A Cross-Sectional Study.

Objective: The aim was to examine the association between dietary selenium intake and nonalcoholic fatty liver disease (NAFLD) in a large group of middle-aged and elderly Chinese persons.Method: The data included in this analysis were from a population-based study, the Xiangya Hospital Health Management Center Study. NAFLD was diagnosed by (1) imaging or histological evidence of hepatic steatosis; (2) absence of specific etiologies of NAFLD; and (3) no heavy consumption of alcohol. Dietary selenium intake was assessed using a validated semi-quantitative food frequency questionnaire. The association between dietary selenium intake and the prevalence of NAFLD was evaluated using logistic and spline regression in a cross-sectional study of 5436 subjects.Results: The prevalence of NAFLD was 36.8%. Compared with the lowest quintile, the energy-adjusted odds ratios for NAFLD were 1.27 (95% confidence interval [CI], 1.07-1.52), 1.30 (95% CI, 1.09-1.55), and 1.58 (95% CI, 1.33-1.89) for the third, fourth, and fifth quintiles of selenium intake, respectively, and there was a positive dose-response relationship (r = 0.88, p for trend = 0.008). Similar results were observed for men and women separately. The findings were not materially altered by adjustment for potential confounders (i.e., age, gender, body mass index, smoking status, diabetes, hypertension, activity level, nutritional supplements, energy intake, fat intake, fiber intake, cholesterol and saturated fatty acid intake).Conclusions: In this middle-aged and elderly population, subjects with higher dietary selenium intake, even below the recommended nutrient intake in China, had higher prevalence of NAFLD in a dose-response relationship manner.

Association between serum zinc and copper concentrations and copper/zinc ratio with the prevalence of knee chondrocalcinosis: a cross-sectional study.

BACKGROUND: Patients with chondrocalcinosis may suffer from a series of symptoms resembling acute gouty arthritis or septic arthritis, but the aetiology and pathogenesis of chondrocalcinosis have not been fully elucidated yet. This study was aimed to assess serum zinc and copper concentrations, as well as the ratio of serum copper to zinc concentrations (Cu/Zn ratio), in relation to the prevalence of knee chondrocalcinosis. METHODS: Data included in this analysis were retrieved from a large population-based cross-sectional study. A bilateral knee anteroposterior radiograph was obtained from each subject. Radiographic knee chondrocalcinosis was diagnosed if definite linear cartilage calcification was detected. Serum zinc and copper concentrations were measured using the spectrophotometric flow injection methods by Roche modular P800. The relations of serum zinc and copper concentrations and Cu/Zn ratio to the prevalence of knee chondrocalcinosis were examined using generalized estimating equations, respectively. RESULTS: The prevalence of knee chondrocalcinosis was 1.2% in the sample of this study (n = 12,362). In comparison with the lowest tertile, the odds ratios (ORs) of knee chondrocalcinosis adjusted by age, sex and body mass index were 0.74 (95% CI 0.50-1.09) in the second and 0.56 (95% CI 0.36-0.86) in the third tertiles of serum zinc concentrations (P for trend = 0.009), were 1.26 (95% CI 0.77-2.05) in the second and 2.01 (95% CI 1.25-3.24) in the third tertile of serum copper concentrations (P for trend = 0.003), and were 1.02 (95% CI 0.61-1.69) in the second and 2.23 (95% CI 1.38-3.59) in the third tertile of Cu/Zn ratio (P for trend < 0.001) respectively. These findings were not materially altered by adjustment for potential confounders. CONCLUSIONS: The present study observed that higher serum zinc concentrations, lower serum copper concentrations or lower Cu/Zn ratio are associated with a lower prevalence of knee chondrocalcinosis in a dose-response relationship manner.

Association between dietary selenium intake and the prevalence of osteoporosis: a cross-sectional study.

OBJECTIVE: To examine the correlation between dietary selenium (Se) intake and the prevalence of osteoporosis (OP) in the general middle-aged and older population in China. METHODS: Data for analyses were collected from a population based cross-sectional study performed at the Xiangya Hospital Health Management Centre. Dietary Se intake was evaluated using a validated semi-quantitative food frequency questionnaire. OP was diagnosed on the basis of bone mineral density scans using a compact radiographic absorptiometry system. The correlation between dietary Se intake and the prevalence of OP was primarily examined by multivariable logistic regression. RESULTS: This cross-sectional study included a total of 6267 subjects (mean age: 52.2 ± 7.4 years; 42% women), and the prevalence of OP among the included subjects was 9.6% (2.3% in men and 19.7% in women). Compared with the lowest quartile, the energy intake, age, gender and body mass index (BMI)-adjusted odds ratios of OP were 0.72 (95% confidence interval [CI] 0.55-0.94), 0.72 (95% CI 0.51-1.01) and 0.47 (95% CI 0.31-0.73) for the second, third and fourth quartiles of dietary Se intake, respectively (P for trend = 0.001). The results remained consistent in male and female subjects. Adjustment for additional potential confounders (i.e., smoking status, drinking status, physical activity level, nutritional supplements, diabetes, hypertension, fibre intake, and calcium intake) did not cause substantial changes to the results. CONCLUSIONS: In the middle-aged and older humans, participants with lower levels of dietary Se intake have a higher prevalence of OP in a dose-response manner.

Relative efficacy and safety of topical non-steroidal anti-inflammatory drugs for osteoarthritis: a systematic review and network meta-analysis of randomised controlled trials and observational studies.

OBJECTIVES: To compare the efficacy and safety of topical non-steroidal anti-inflammatory drugs (NSAIDs), including salicylate, for the treatment of osteoarthritis (OA). METHODS: PubMed, Embase, Cochrane Library and Web of Science were searched from 1966 to January 2017. Randomised controlled trials (RCTs) comparing topical NSAIDs with placebo or each other in patients with OA and observational studies comparing topical NSAIDs with no treatment or each other irrespective of disease were included. Two investigators identified studies and independently extracted data. Bayesian network and conventional meta-analyses were conducted. The primary outcomes were pain relief for RCTs and risk of adverse effects (AEs) for observational studies. RESULTS: 43 studies, comprising 36 RCTs (7 900 patients with OA) and seven observational studies (218 074 participants), were included. Overall, topical NSAIDs were superior to placebo for relieving pain (standardised mean difference (SMD)=-0.30, 95% CI -0.40 to -0.20) and improving function (SMD=-0.35, 95% CI -0.45 to -0.24) in OA. Of all topical NSAIDs, diclofenac patches were most effective for OA pain (SMD=-0.81, 95% CI -1.12 to -0.52) and piroxicam was most effective for functional improvement (SMD=-1.04, 95% CI -1.60 to -0.48) compared with placebo. Although salicylate gel was associated with higher withdrawal rates due to AEs, the remaining topical NSAIDs were not associated with any increased local or systemic AEs. CONCLUSIONS: Topical NSAIDs were effective and safe for OA. Diclofenac patches may be the most effective topical NSAID for pain relief. No serious gastrointestinal and renal AEs were observed in trials or the general population. However, confirmation of the cardiovascular safety of topical NSAIDs still warrants further observational study.

Association Between Magnetic Resonance Imaging-Measured Intercondylar Notch Dimensions and Anterior Cruciate Ligament Injury: A Meta-analysis.

PURPOSE: To explore the association between the magnetic resonance imaging (MRI)-measured intercondylar notch dimensions, including the intercondylar notch width (NW) and intercondylar notch width index (NWI), and the risk of anterior cruciate ligament (ACL) injury by performing a meta-analysis of studies that relied on the multiplanar imaging and soft-tissue visualization strengths of MRI. METHODS: The MEDLINE, Embase, and SportDiscus databases were searched from inception to March 2017. Observational studies reporting on the associations of the NWI and NW with ACL injury were retrieved. A random-effects model was used to calculate the overall weighted mean difference (WMD) between the ACL injury group and control group. RESULTS: A total of 20 studies were included in this meta-analysis. The combined data showed that subjects with ACL injury, as compared with the control group, had a significantly decreased NW (pooled WMD, -1.53 [95% confidence interval, -1.81 to -1.25]; P < .00001) and NWI (pooled WMD, -0.02 [95% confidence interval, -0.03 to -0.01]; P < .00001). Similar findings were observed in subgroup analyses in terms of different injury mechanisms. No significant difference in NWI was found in the axial view. A significantly decreased NW and NWI were found in other plane views. The sensitivity analyses after the exclusion of studies enrolling only athletes or skeletally immature subjects reached similar outcomes. The Begg rank correlation test showed no publication bias. CONCLUSIONS: With the accumulation of evidence, this meta-analysis concluded that the NW and/or NWI measured by MRI was significantly lower in ACL-injured patients than in control subjects. For persons with a narrow intercondylar notch, preventive measures can be prepared for the prevention of ACL injuries. LEVEL OF EVIDENCE: Level III, meta-analysis of Level II and III studies.

[Association between red blood cell volume distribution width and osteophytes: A cross-sectional study].

OBJECTIVE: To investigate the association between red blood cell volume distribution width (RDW) and osteophytes.
 Methods: This cross-sectional study was conducted in the Department of Health Examination Center of Xiangya Hospital, Central South University in Changsha, Hunan Province, China. A total of 8 334 subjects were included in this study. The severity of osteophytes was graded using the criteria of the Osteoarthritis Research Society International (OARSI). Osteophytes incident was defined as at least one side of the knee had a osteophytes grade ≥1. According to the quartiles of the RDW level, the subjects were divided into 4 groups. Multivariate logistic regression analysis was used to calculate the odds ratio (OR) and the 95% confidence interval (CI) of the knee osteophytes incidence between each RDW group and the lowest level group. Tests for linear trends were conducted based on logistic regression using a median variable of RDW level in each category.
 Results: Quartile 1 (Q1), RDW≤9.78; Q2, 9.7813.10. The multivariable adjusted ORs (95%CI) of the prevalence of osteophytes were 1.38 (1.06 to 1.79) in the second percentile interval, and 1.27 (0.97 to 1.66) and 1.50 (1.15 to 1.94) in the third and fourth percentile interval, respectively. Test for linear trends suggested that there was a positive association between the RDW level and the risk of knee osteophytes incidence (P=0.019).
 Conclusion: The risk of osteophytes incidence increases with the increasing RDW levels.

Relationship between cigarette smoking and hyperuricemia in middle-aged and elderly population: a cross-sectional study.

The aim of the study was to estimate the cross-sectional association between cigarette smoking and the prevalence of hyperuricemia (HU) in the middle-aged and elderly males and females. A total of 3415 males and 2932 females were included in this study. HU was defined as SUA≥ 416 mmol/L for males and ≥360 mmol/L for females. The smoking status was classified into four categories based on daily smoking habit: (1) 0/day; (2) 1-10/day; (3) 11-20/day; and (4) >20/day. Multivariable logistic regressions were conducted to examine the aforementioned association. The prevalence of HU in the male and female sample was 25.0 and 10.0 %, respectively. In male subjects, the prevalence of HU in smokers (22.8 %) was significantly lower than that in non-smokers (26.5 %) (p = 0.016). Meanwhile, with adjustment for potential confounding factors, the prevalence of HU in smokers was still lower (OR = 0.83, 95 % CI 0.70-0.98, P = 0.033). Furthermore, a significantly inverse association between smoking status and HU was observed in the multivariable model. The multivariable-adjusted OR (95 % CI) for HU in the second, third and fourth category of smoking status was 0.84 (95 % CI 0.66-1.06), 0.90 (95 % CI 0.69-1.18) and 0.76 (95 % CI 0.58-0.99), respectively, compared with that in the first category. A clear trend (P for trend was 0.036) was observed. However, there was no significant association between cigarette smoking and HU in female subjects (P for trend was 0.739). This study indicated an inverse association between cigarette smoking and the prevalence of HU in the middle-aged and elderly male population, independent of some major confounding factors. The findings of this study expect further prospective studies to confirm the causal relationship.

Association between metabolic syndrome and knee osteoarthritis: a cross-sectional study.

BACKGROUND: Osteoarthritis (OA) is the most prevalent chronic joint disease in China. The aim of this study was to examine the association between metabolic syndrome (MetS) and knee OA in a population-based Chinese study. METHODS: Data included in this analysis is from a cross-sectional study, i.e., the Xiangya Hospital Health Management Center Study. MetS was diagnosed according to the criteria defined by the Chinese Diabetes Society. Radiographic knee OA was defined as changes equivalent to Kellgren-Lawrence (K-L) grade 2 or above at least one side. Associations between MetS and its components with OA were evaluated by conducting multivariable adjusted logistic regression. RESULTS: A total of 5764 participants were included in the present study. The unadjusted OR (1.27, 95%CI: 1.10-1.47, P = 0.001), age-sex adjusted OR (1.17, 95%CI: 1.01-1.36, P = 0.041) and multivariable adjusted OR (1.17, 95%CI: 1.01-1.36, P = 0.043) all suggested a positive association between MetS and knee OA. Besides, its components (e.g., overweight, hypertension and dyslipidemia) were also associated with the prevalence of radiographic knee OA respectively, after adjusting for some confounding factors. In addition, with the accumulation of MetS components, the prevalence of knee OA increased. Furthermore, MetS as a whole was associated with the prevalence of knee osteophyte (OSP) (OR = 1.72, 95%CI: 1.42-2.09, P < 0.001), but not joint space narrowing (JSN) (OR = 1.06, 95%CI: 0.91-1.23, P = 0.449). CONCLUSIONS: The findings of the present study indicated that there was a positive association between the prevalence of MetS and knee OA. However, MetS as a whole was associated with the higher prevalence of knee OSP, but not JSN, which should shed light on our understanding the association between MetS and OA.

Association Between Tibial Plateau Slopes and Anterior Cruciate Ligament Injury: A Meta-analysis.

PURPOSE: To investigate the associations of medial tibial plateau slope (MTPS), lateral tibial plateau slope (LTPS), and coronal tibial plateau slope (CTPS) with anterior cruciate ligament (ACL) injury both in the general population and in different gender subgroups. METHODS: PubMed, Ovid, Embase, and Scopus databases were searched through from inception to August 31, 2016. Observational studies reporting associations of MTPS/LTPS/CTPS with ACL injury were retrieved for analysis. Either a fixed- or random-effects model was used to calculate the overall standardized mean difference (SMD). Reviews, meeting abstracts, cadaver or animal studies, and other studies without disclosing full text were excluded in this study. RESULTS: A total of 29 studies were included. Subjects with ACL injury exhibited a significant increase in MTPS (SMD: 0.34 [95% confidence interval (CI): 0.18, 0.49]; P < .0001) and LTPS (SMD: 0.49 [95% CI: 0.30, 0.68]; P < .00001), but not in the CTPS (SMD: 0.09 [95% CI: -0.10, 0.27]; P = .36), compared with controls. Meanwhile, significant differences in MTPS and LTPS were observed in the male subgroup (SMD: 0.41 [95% CI: 0.20, 0.62]; P = .0001 and SMD: 0.55 [95% CI: 0.26, 0.85]; P = .0002, respectively) but not in the female (SMD: 0.31 [95% CI: -0.02, 0.64]; P = .06 and SMD: 0.26 [95% CI: -0.04, 0.56]; P = .09, respectively). CONCLUSIONS: The present meta-analysis showed that the increases in MTPS and LTPS were overall risk factors of ACL injury. However, these slopes would only be considered as "at risk" for males, but not for females. In addition, it was also proved that CTPS was not a risk factor of ACL injury. LEVEL OF EVIDENCE: Level III, meta-analysis of Level II and III studies.

Relationship between cigarette smoking and radiographic knee osteoarthritis in Chinese population: a cross-sectional study.

The purpose of this paper was to estimate the cross-sectional association between cigarette smoking and radiographic knee Osteoarthritis (OA) in Chinese population. A total of 3,789 subjects (1,796 females and 1,993 males) participated in this study. A subject was diagnosed with radiographic knee OA if Kellgren-Lawrence (K-L) grade ≥2 in at least one leg. The smoking status was classified into four levels based on the daily smoking habit: (1) 0/day; (2) 1-10/day; (3) 11-20/day; and (4) >20/day. Linear trend and multivariable logistic regression were conducted for statistical analysis. The prevalence of radiographic knee OA was 28.4 % among the subjects of this study. An inverse association was observed between cigarette smoking and radiographic knee OA in the linear trend test. Such association remained valid after adjusting the factors of age, gender, body mass index, betel quilt chewing status, physical activity, alcohol drinking status, mean total energy intake and educational level in the multivariable logistic regression. This study suggested a negative association between cigarette smoking and radiographic knee OA in the Chinese population. The findings of this study need to be confirmed by further prospective research.

Trends and benefits of early hip arthroplasty for femoral neck fracture in China: a national cohort study.

BACKGROUND: Limited studies have examined the benefits of early arthroplasty within 48 h from admission to surgery for femoral neck fractures (FNFs). Using the national inpatient database, the authors aimed to investigate the trends in early arthroplasty within 48 h for FNFs in China and to assess its effect on in-hospital complications and 30-day readmission patterns. MATERIALS AND METHODS: This was a retrospective cohort study. Patients receiving primary total hip arthroplasty (THA) or hemiarthroplasty (HA) for FNFs in the Hospital Quality Monitoring System between 2013 and 2019 were included. After adjusting for potential confounders with propensity score matching, a logistic regression model was performed to compare the differences in in-hospital complications [i.e. in-hospital death, pulmonary embolism, deep vein thrombosis (DVT), wound infection, and blood transfusion], rates and causes of 30-day readmission between early and delayed arthroplasty. RESULTS: During the study period, the rate of early THA increased from 18.0 to 19.9%, and the rate of early HA increased from 14.7 to 18.4% ( P <0.001). After matching, 11 731 pairs receiving THA and 13 568 pairs receiving HA were included. Compared with delayed THA, early THA was associated with a lower risk of pulmonary embolism [odds ratio (OR) 0.51, 95% CI: 0.30-0.88], DVT (OR 0.59, 95% CI: 0.50-0.70), blood transfusion (OR 0.62, 95% CI: 0.55-0.70), 30-day readmission (OR 0.82, 95% CI: 0.70-0.95), and venous thromboembolism-related readmission (OR 0.50, 95% CI: 0.34-0.74). Similarly, early HA was associated with a lower risk of DVT (OR 0.70, 95% CI: 0.61-0.80) and blood transfusion (OR 0.74, 95% CI: 0.68-0.81) than delayed HA. CONCLUSION: Despite a slight increase, the rate of early arthroplasty remained at a low level in China. Given that early arthroplasty can significantly improve prognosis, more efforts are needed to optimize the procedure and shorten the time to surgery.